In a manufacturing process of an array substrate, a glass substrate is first to be made into a semi-finished array substrate before being manufactured into a finished array substrate. In such a process, it is necessary to clean objects to be cleaned, such as the glass substrate and the semi-finished array substrate, through a plurality of cleaning steps that are typically performed in one single cleaning device.
The cleaning device can comprise a first cleaning unit which can remove organics from an object to be cleaned using ultraviolet light; a second cleaning unit which can remove particles from the object to be cleaned using water and gases; a third cleaning unit which can remove organics and metal ions from the object to be cleaned using ozone water, or can oxidize amorphous silicon (i.e., a-Si) on the object to be cleaned using ozone water, so as to form a silicon oxide (i.e., SiOx) layer on a surface of the a-Si; a fourth cleaning unit which can remove the SiOx layer through hydrofluoric acid etching; a fifth cleaning unit for second removal of particles from the object to be cleaned using hydrogen water; a sixth cleaning unit which can oxidize the surface of the a-Si on the object to be cleaned into a homogeneous and compact SiOx layer using ozone water; a seventh cleaning unit which can remove particles from the object to be cleaned using water and a gas; and an air-dying unit which can blow-dry the object to be cleaned.
When the cleaning device is used to clean a glass object to be cleaned, such as a glass substrate, it is only necessary for the glass object to be successively cleaned by the first, the second, the third, and the seventh cleaning units, and the air-dying unit, while the fourth, the fifth, and the sixth cleaning units will be left unused. In the entire cleaning procedure, however, the object to be cleaned has to pass through the fourth, the fifth, and the sixth cleaning units as well, which, after being frequently used, would very likely be subjected to liquid leakage. As a result, liquid leakages thereof might drip onto the glass substrate passing therethrough. As the hydrofluoric acid of the fourth cleaning unit can corrode a glass substrate, where the hydrofluoric acid drips onto the glass substrate, the glass substrate after being cleaned will become useless.